Display apparatus and method of displaying three dimensional images using the same

ABSTRACT

A display apparatus includes a display panel, a light source part and a directional light projecting element. The display panel displays a first image during a first subframe and a different second image during a second subframe. The light source part provides light to the display panel. The directional light projecting element is disposed between the display panel and the light source part. The directional light projecting element includes a barrier part and a lens part disposed above the barrier part. The barrier part has a plurality of barriers defined as a plurality of first electrodes and a plurality of second electrodes crossing the first electrodes. The lens part has a plurality of lenses disposed in a first direction and a second direction crossing the first direction. Each of the lenses corresponds to a subset of plural lenses among the plurality of the barriers.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Korean Patent Application No.10-2012-0095843, filed on Aug. 30, 2012, and all the benefits accruingtherefrom under 35 U.S.C. §119, the contents of which application areherein incorporated by reference in their entireties.

BACKGROUND

1. Field of Disclosure

Exemplary embodiments of the present invention relate to a displayapparatus and a method of displaying three-dimensional (“3D”) imagesusing the display apparatus. More particularly, exemplary embodiments ofthe present invention relate to a display apparatus improving a displayquality and a method of displaying 3D images using the displayapparatus.

2. Description of Related Technology

Generally, a liquid crystal display apparatus produces a two-dimensional(“2D”) image. Recently, as a demand for displaying a 3D image have beenincreasing in the video gaming and movie industries, liquid crystaldisplay apparatuses have been developed for creating a perception of 3Dimages.

Generally, a stereoscopic image displaying apparatus creates aperception of a 3D image by using a binocular parallax phenomenonbetween the two eyes of a human being. For example, as the two eyes of ahuman are spaced apart from each other, images viewed at differentangles are inputted to the human brain. The human brain then mixes theimages so that a viewer may recognize the stereoscopic image as a 3Done.

Stereoscopic image displaying devices may be divided into a stereoscopictype and an auto-stereoscopic type depending on whether a viewer wears aspecial pair of spectacles for creating the 3D effect or not. Thestereoscopic type may include an anaglyph type and a shutter glass typeand so on. In the anaglyph type, a blue spectacle and a red spectaclemay be required for the viewer to wear. In the shutter glass type, aleft image and a right image may be temporally divided to beperiodically displayed, and a viewer wears correspondingly synchronizedshutter glasses which open and close a left eye LE shutter and a righteye RE shutter in synchronization with the displaying of the left andright images.

The auto-stereoscopic type may include a lenticular type and a barriertype. In the lenticular type, a lenticular lens having a plurality offocal points is used. The 2D image is refracted by the lenticular lensat the focal points so that the 3D image is displayed. In the barriertype, a plurality of barriers selectively cover different areas of adisplay panel. The barriers thus selectively block an image on thedisplay panel so that a left image portion and a right image portionbecome different from each other. Thus, the 2D image is converted intothe 3D image by use of the barriers, typically in combination withshutter glasses or other means.

When two eyes of a viewer are disposed in a horizontal direction alignedwith a corresponding horizontal axis of the display device, the 3D imageis well recognized to the viewer in the auto-stereoscopic type displaydevice. However, when two eyes of the viewer are disposed in a verticaldirection that crosses with a horizontal axis of the display device, orin a direction inclined with respect to the horizontal direction of thedisplay device, the 3D image may not be shown to the viewer. This isparticularly a problem with mobile or portable displays such as found insmartphones and tablet computers where the user can easily rotate theapparatus to have different angles relative to the normal horizontalline of the eyes.

It is to be understood that this background of the technology section isintended to provide useful background for understanding the heredisclosed technology and as such, the technology background section mayinclude ideas, concepts or recognitions that were not part of what wasknown or appreciated by those skilled in the pertinent art prior tocorresponding invention dates of subject matter disclosed herein.

BRIEF SUMMARY

The present disclosure of invention provides a display apparatus capableof properly presenting a three-dimensional (“3D”) image according to aviewer irrespective of the relative angle made between the normalhorizontal of the display and the eye-to-eye connection line of the twoeyes of a viewer.

Exemplary embodiments of the present disclosure also provide a method ofdisplaying the 3D image using the display apparatus.

In an exemplary embodiment of a display apparatus according to thepresent disclosure, the display apparatus includes a display panel, alight source part and a directional light projecting element. Thedisplay panel displays a first image during a first subframe and adifferent second image during a second subframe. The light source partprovides backlighting light to the display panel. The directional lightprojecting element is disposed between the display panel and the lightsource part. The directional light projecting element includes a barrierpart and a lens part disposed above the barrier part. The barrier parthas a plurality of barriers defined as a plurality of first electrodesand a plurality of second electrodes crossing the first electrodes. Thelens part has a plurality of lenses disposed in a first direction and asecond direction crossing the first direction. Each of the lensescorresponds to a subset of plural and adjacent barriers among theplurality of barriers.

In an exemplary embodiment, one lens may correspond to the barriersdisposed in an M by M matrix. M is a positive integer equal to orgreater than 2.

In an exemplary embodiment, the lens have a refracting portion ofcircular shape

In an exemplary embodiment, centers of four lenses adjacent to eachother form a square.

In an exemplary embodiment, centers of three lenses adjacent to eachother form an isometric triangle.

In an exemplary embodiment, the lens part further comprises a lightblocking material disposed where the lenses are not disposed.

In an exemplary embodiment, a bottom portion of each lens may have asquare shape and an upper portion of each lens has a circular shape.

In an exemplary embodiment, a bottom portion of the lens may have aregular hexagonal shape and an upper portion of the lens has a circularshape.

In an exemplary embodiment, a proper distance for a viewer to view athree-dimensional (“3D”) image from a principal point of the lens is D,a focal length of the lens is f, a distance between the principal pointof the lens and the barrier part is d and a refractive index of the lensis n.

$d = {\frac{n}{\left( {\frac{1}{f} - \frac{1}{D}} \right)}.}$

In an exemplary embodiment, a display area of a viewpoint imagecorresponding to one eye of the viewer at the proper distance D is PE, apitch of a barrier unit, which includes the barriers corresponding toone lens, in the first direction is Pb.

${Pb} = {2 \times {PE} \times {\frac{d}{n \times D}.}}$

In an exemplary embodiment, a pitch of the lens in the first directionis Pl.

${Pl} = {{Pb} \times {\frac{D}{D + \frac{d}{n}}.}}$

In an exemplary embodiment, a side dimension of the projected area PE ofthe viewpoint image corresponding to one eye of the viewer at the properdistance D may be a distance between two eyes of the viewer.

In an exemplary embodiment, the display panel may be operated in ahorizontal mode, in which two eyes of a viewer are disposed in ahorizontal direction, or in a vertical mode, in which two eyes of theviewer are disposed in a vertical direction. The barriers havingtransmitting states may be disposed as lines extending in the verticaldirection in the horizontal mode. The barriers having the transmittingstates are disposed as lines extending in the horizontal direction inthe vertical mode.

In an exemplary embodiment, the display panel may be operated in aninclination mode, in which two eyes of a viewer are disposed in adirection inclined with respect to the display panel. The barriershaving transmitting states may be disposed as lines extending in adirection substantially perpendicular to a line connecting two eyes ofthe viewer in the inclination mode.

In an exemplary embodiment, the display apparatus may further include aviewpoint detector and/or determiner configured for tracking and/ordetermining a viewpoint of a viewer relative to the display panel.

In an exemplary embodiment, the transmitting states of the barriers ofthe barrier part and the blocking states of the barriers of the barrierpart may be adjusted according to a move of the viewpoint of the viewer.

In an exemplary embodiment of a method of displaying a three-dimensional(“3D”) image according to the present disclosure of invention, themethod includes providing first image data to a display panel during afirst subframe and second image data to the display panel during asecond subframe, providing backlighting light to the display panel,selectively transmitting the light from a light source part using abarrier part, the barrier part having a plurality of barriers defined asa plurality of first electrodes and a plurality of second electrodescrossing the first electrodes and refracting the light from the barrierpart using a lens part, the lens part having a plurality of lensesdisposed in a first direction and a second direction crossing the firstdirection, each of the lenses corresponding to a plurality of thebarriers.

In an exemplary embodiment, one lens may correspond to the barriersdisposed in an M by M matrix. M is a positive integer equal to orgreater than 2.

In an exemplary embodiment, a proper distance for a viewer to view the3D image from a principal point of the lens is D, a focal length of thelens is f, a distance between the principal point of the lens and thebarrier part is d and a refractive index of the lens is n.

$d = {\frac{n}{\left( {\frac{1}{f} - \frac{1}{D}} \right)}.}$

In an exemplary embodiment, a display area of a viewpoint imagecorresponding to one eye of the viewer at the proper distance D is PE, apitch of a barrier unit, which includes the barriers corresponding toone lens, in the first direction is Pb.

${Pb} = {2 \times {PE} \times {\frac{d}{n \times D}.}}$

In an exemplary embodiment, a pitch of the lens in the first directionis Pl.

${Pl} = {{Pb} \times {\frac{D}{D + \frac{d}{n}}.}}$

According to the display apparatus and the method of displaying the 3Dimage using the display apparatus, the display apparatus includesbarriers disposed in a matrix form and lenses corresponding to thebarriers so that the display apparatus may properly represent the 3Dimage according to a direction of two eyes of a viewer relative to apredefined axis of the display panel.

Other aspects of the present disclosure of invention will becomeapparent from the below more detailed descriptions.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present disclosure ofinvention will become more apparent by describing in detailed exemplaryembodiments thereof with reference to the accompanying drawings, inwhich:

FIG. 1 is a perspective view illustrating a display apparatus accordingto an exemplary embodiment of the present disclosure;

FIG. 2A is a conceptual diagram illustrating images provided to a righteye RE of a viewer by a display panel and a first operational state ofthe directional light projecting element of FIG. 1 in a first subframe;

FIG. 2B is a conceptual diagram illustrating images provided to a lefteye LE of the viewer by the display panel and a second operational stateof the directional light projecting element of FIG. 1 in a secondsubframe;

FIG. 3 is a plan view illustrating a barrier part of FIG. 1;

FIG. 4 is a plan view illustrating a lens part of FIG. 1 which in onespecific embodiment, has a plurality of frusto spherical lenses eachaligning over a corresponding four barrier pixels of the barrier part ofFIG. 3;

FIG. 5 is a conceptual diagram illustrating a display area of the imageshown to the viewer at a proper distance by the display panel and thedirectional light projecting element of FIG. 1;

FIG. 6 is a conceptual diagram illustrating a plurality of barrierspixels (or more simply herein, “barriers”) corresponding to one lens ofFIG. 4;

FIGS. 7A and 7B are conceptual diagrams corresponding to states of thebarriers corresponding to one lens of FIG. 1 in a horizontal mode;

FIGS. 8A and 8B are conceptual diagrams corresponding to states of thebarriers corresponding to one lens of FIG. 1 in a vertical mode;

FIG. 9 is a conceptual diagram illustrating a plurality of barrierscorresponding to one lens of a display apparatus according to anexemplary embodiment;

FIGS. 10A and 10B are conceptual diagrams corresponding to states of thebarriers corresponding to one lens of FIG. 9 in a horizontal mode;

FIGS. 11A and 11B are conceptual diagrams corresponding to states of thebarriers corresponding to one lens of FIG. 9 in a vertical mode;

FIGS. 12A and 12B are conceptual diagrams corresponding to states of thebarriers corresponding to one lens of FIG. 9 in an inclination mode;

FIGS. 13A to 13C are conceptual diagrams corresponding to states of thebarriers corresponding to one lens of FIG. 9 when a viewpoint of theviewer moves;

FIG. 14 is a plan view illustrating a lens part according to anexemplary embodiment;

FIG. 15 is a plan view illustrating a lens part according to anexemplary embodiment;

FIG. 16 is a plan view illustrating a lens part according to anexemplary embodiment;

FIG. 17A is a plan view illustrating a lens part according to anexemplary embodiment;

FIG. 17B is a cross-sectional view cut along a line I-I′ in FIG. 17A;

FIG. 18A is a plan view illustrating a lens part according to anexemplary embodiment; and

FIG. 18B is a cross-sectional view cut along a line II-IF in FIG. 18A.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments in accordance with the presentdisclosure of invention will be described in further detail withreference to the accompanying drawings.

FIG. 1 is a perspective view illustrating a display apparatus accordingto a first exemplary embodiment.

Referring to FIG. 1, the display apparatus includes a light source part100, a display panel 200, a directional light projecting element 300, alight source driver 400, a display panel driver 500 and a barrier driver600. The display apparatus may further include a viewpointdetector/determiner 700 which detects and/or determines a relativeviewpoint relation between the two eyes of the viewer and major axis ofthe display panel 200 (e.g., rotated 90 degrees, upside down, etc.).

The light source part 100 provides a backlighting light to the displaypanel 200. The light source part 100 includes one or more light sourcesconfigured for generating light. For example, the light source mayinclude a cold cathode fluorescent lamp (“CCFL”), an external electrodefluorescent lamp (“EEFL”), a flat fluorescent lamp (“FFL”), a lightemitting diode (“LED”).

The light source part 100 may be a direct backlighting type of lightsource part which is disposed under the display panel 200 to providelight in line directly to the display panel 200. Alternatively, thelight source part 100 may be an edge type of backlighting light sourcepart which is disposed corresponding to an edge of the display panel 200to provide a light to the display panel 200. When the light source part100 is the edge type light source part, the light source part 100 mayfurther include a light guide plate (LGP, not shown).

The display panel 200 selectively modulates light rays that it receivesfrom the light source part 100 so as to thereby form an image. Thedisplay panel 200 is disposed on the light source part 100. The displaypanel 200 includes a plurality of respective, image-defining pixels. Thepixels may be disposed in a matrix pattern and they may be of a muchfiner resolution than so-called, barrier pixels described herein. (Inother words, that can be many image-defining pixels for each one barrierpixel.) The display panel includes a first panel substrate (e.g., apixel electrodes supporting substrate, not shown), a second panelsubstrate (e.g., a common electrode supporting substrate, not shown)facing the first panel substrate and a liquid crystal layer (not shown)disposed between the first and second panel substrates.

The directional light projecting element 300 is disposed between thelight source part 100 and the display panel 200 and operates toselectively determine a light rays projecting state for light raysprojected through the display panel 200 (e.g., tilted left, tiltedright, tilted up, tilted down). The directional light projecting element300 includes a barriers part 320 and a lenses part 340. The directionallight projecting element 300 selectively adjusts the light-raysprojecting angle from the light source part 100 to the display panel 200to thereby control the converting of a 2D image present on the surfaceof the display panel 200 into a 3D image as perceived by the viewer whenin a corresponding viewpoint orientation relative to the display panel200.

A method of converting the 2D image into the 3D image by use of thedirectional light projecting element 300 is now explained whilereferring to FIGS. 2A and 2B in more detail.

The barrier part 320 is disposed above the light source part 100. Thebarrier part 320 includes a plurality of barrier pixels (or more simplyherein, “barriers”) which are selectively closed or opened to therebyselectively block or pass through light rays from corresponding regionsof the light source part 100 toward the lenses part 340. In other words,the barriers selectively transmit or block their respective light raysfrom reaching corresponding areas of the lenses part 340 after departingfrom the light source part 100.

The barrier part 320 includes a plurality of first electrodes eachextending in a first direction and a plurality of second electrodes eachextending in a second and different direction and thus crossing with thefirst electrodes. The barriers are defined by the crossing regions ofthe first electrodes and the second electrodes and by liquid crystalmaterial disposed therebetween. The barriers are disposed in a matrixform.

More specifically, the barrier part 320 includes a first barriersubstrate, a second barrier substrate facing the first barriersubstrate, a barrier liquid crystal layer disposed between the first andsecond barrier substrates and at least one polarizing sheet or plateassociated with the barrier part 320 (where an orthogonal secondpolarizing sheet or plate may be formed on the bottom of the displaypanel 200).

The first electrodes may be formed on the first barrier substrate. Thesecond electrodes may be formed on the second barrier substrate.According to voltages applied to the first and second electrodes, thebarrier of the barrier part 320 has a transmitting state or a blockingstate.

The barriers may have transmitting states along a specific direction.The barriers may have blocking states along the specific direction. InFIG. 1, the barriers have the transmitting states along a seconddirection D2. The direction of the barriers having the transmittingstates may vary according to a mode of the display panel 200.

For example, the display panel 200 may be operated according to ahorizontal mode, in which two eyes of the viewer are disposed in ahorizontal direction, or in a vertical mode, in which two eyes of theviewer are disposed in a vertical direction. In the horizontal mode, thebarriers having the transmitting states are disposed in the verticaldirection. In the vertical mode, the barriers having the transmittingstates are disposed in the horizontal direction.

For example, the display panel 200 may be operated in an inclinationmode. In the inclination mode, two eyes of the viewer are disposed in aninclined direction with respect to the display panel 200. In theinclination mode, the barriers having the transmitting states aredisposed in a direction substantially perpendicular to a line connectingtwo eyes of the viewer. Alternating lines of light ray blocking barriersand light ray passing barriers reciprocate back and forth so as toalternatingly direct their projected light rays (with aid of thecorresponding lenses) to the left eye and then the right eye and thenthe left eye again, etc.

A structure of the barrier part 320 is explained referring to FIG. 3 indetail.

The lens part 340 is disposed above the barrier part 320. The lens part340 refracts the light rays that are selectively passed through thebarrier part 320 to thereby transmit those light rays at selectedprojecting angles to and through the display panel 200 and then to theviewer's left and right eyes.

The lens part 340 includes a plurality of lenses. The lenses aredisposed as rows extending in a first direction D1 and as columnsextending in the second direction D2. Each of the lenses covers an areacorresponding to a plurality of the barriers. For example, one lens maycover an area corresponding to smaller barriers disposed in that samearea as an M by M matrix of barriers. Herein, M is a positive integerequal to or greater than two.

A structure of the lens part 340 for the case of M=2 is explainedreferring to FIG. 6 as an example.

Referring to FIG. 1, the light source driver 400 is connected to drivethe light source part 100. In one embodiment, the light source driver400 is further connected (not shown) to the display panel driver 500 sothat operations of the two are coordinated. The light source driver 400generates one or more light source driving voltages for drivingrespective light sources. The light source driver 400 receives a lightsource control signal from outside. The light source driver 400generates the light source driving voltage based on the light sourcecontrol signal. The light source driver 400 outputs the light sourcedriving voltage to the light source part 100. The light source driver400 may include a DC (direct current) to DC converter.

The light source driver 400 may be disposed under the light source part100. The light source driver 400 may be disposed outside of a lightsource receiving container (not shown) and facing a bottom surface ofthe receiving container.

The display panel driver 500 is connected to the display panel 200. Thedisplay panel driver 500 generates a panel driving signal for drivingthe display panel 200. The display panel driver 500 drives the displaypanel 200 by dividing a single frame into N subframes. Here, N is apositive integer equal to or greater than two. For example, N may be twowhere a first subframe defines an image to be projected to the left eyeand a second subframe defines an image to be projected to the right eye.

More specifically and as an example, the display panel driver 500divides a single 3D frame into a first subframe and a second subframe.The first subframe may be an odd-numbered frame. The second subframe maybe an even-numbered frame. The display panel driver 500 provides firstimage to the display panel 200 during the first subframe. The displaypanel 200 displays a first image during the first subframe. The displaypanel driver 500 provides second image to the display panel 200 duringthe second subframe. The display panel 200 displays a second imageduring the second subframe.

The display panel driver 500 includes a gate lines driver and a datalines driver.

The gate lines driver generates gate signals for driving the gate linesof the display panel 200. The gate lines driver outputs the gate signalsto the gate lines. The gate lines driver sequentially outputs the gatesignals to the gate lines so that the display panel 200 is driven by ascanning driving method.

The data lines driver generates data voltages for driving the data linesof the display panel 200. The data lines driver outputs the datavoltages to the data lines.

The display panel driver 500 may adjust the image of the display panel200 based on viewpoint tracking/determining information received fromthe viewpoint detector/determiner 700. For example, the display paneldriver 500 may determine the horizontal mode and the vertical mode ofthe display panel 200 based on the viewpoint tracking information.Alternatively, the display panel driver 500 may determine the horizontalmode and the vertical mode of the display panel 200 based on a user'ssetting.

The barrier driver 600 is connected to the barrier part 320. The barrierdriver 600 generates a barrier driving signal for driving the barrierpart 320. The barrier driver 600 drives the barrier part 320 by dividinga single frame into N subframes.

For example, the barrier driver 600 divides a single frame into a firstsubframe and a second subframe. The barrier driver 600 controls a firstgroup of the barriers and a second group of the barriers so that thebarriers in the first group have the transmitting states during thefirst subframe and the barriers in the second group have the blockingstates during the first subframe but the situation flips for the secondsubframe and then it is the barriers in the second group that havetransmitting states during the second subframe.

The barrier driver 600 may drive the barrier part 320 using theviewpoint tracking information received from the viewpoint detector 700.The barrier driver 600 may switch the transmitting states of thebarriers and the blocking states of the barriers according to a move ofthe viewpoint of the viewer.

The viewpoint detector 700 detects the viewpoint of the viewer. Theviewpoint detector 700 may determine positions of two eyes of the viewerand/or a position of the display device relative to gravity. Inaddition, the viewpoint detector 700 may determine an inclined angle oftwo eyes of the viewer based on the positions of two eyes of the viewer.The viewpoint detector 700 detects the viewpoint of the viewer andoutputs the viewpoint tracking information to the display panel driver500 and the barrier driver 600.

The viewpoint detector 700 may include a camera. The viewpoint detector700 may be disposed at a bezel portion of a receiving containerreceiving the display panel 200.

FIG. 2A is a conceptual diagram illustrating images provided to a righteye RE of the viewer by the display panel 200 and by the directionallight projecting element 300 of FIG. 1 in the first subframe. FIG. 2B isa conceptual diagram illustrating images provided to a left eye LE ofthe viewer by the display panel 200 and by the directional lightprojecting element 300 of FIG. 1 in the second subframe.

Hereinafter, a method of displaying the 3D image of the displayapparatus when the display panel 200 is driven by dividing frames intothe first subframe and the second subframe is explained in detailreferring to FIGS. 1, 2A and 2B.

Referring to FIG. 2A, the display panel 200 displays a first image RI inthe first subframe. The first image RI may represent a right imageintended for the right eye RE of the viewer.

During the first subframe, the barriers in the first group havetransmitting states and the barriers in the second group have blockingstates. The barriers in the first group and the barriers in the secondgroup may be alternately disposed with each other in the horizontaldirection in the horizontal mode. The barriers in the first group andthe barriers in the second group may be alternately disposed with eachother in the vertical direction in the vertical mode.

During the first subframe, the light rays from the light source part 100have respective first paths, which are focused toward the right eye REof the viewer, where the respective first paths are determined by thebarriers in the first group having the transmitting states and by theportions of the lenses of the lens part 340 through which the light raysof the non-blocking barriers pass.

Thus, the right eye RE of the viewer views the right image RI based onthe light having the first path during the first subframe.

Referring to FIG. 2B, the display panel 200 displays second image LI inthe second subframe. The second image LI may represent a left image forthe left eye LE of the viewer.

During the second subframe, the barriers in the first group haveblocking states and the barriers in the second group have transmittingstates. The barriers in the first group and the barriers in the secondgroup may be alternately disposed with each other in the horizontaldirection in the horizontal mode. The barriers in the first group andthe barriers in the second group may be alternately disposed with eachother in the vertical direction in the vertical mode.

During the second subframe, the light rays from the light source part100 have respective second paths, which are focused toward the left eyeLE of the viewer, where the respective second paths are determined bybarriers in the second group having the transmitting states and be theportions of the lenses of the lens part 340 through which the light raysof the non-blocking barriers pass.

Thus, the left eye LE of the viewer views the left image LI based on thelight having the second path during the second subframe.

Therefore, the brain of the viewer temporally mixes the right images RIinputted for the right eye RE and the left images LI inputted from theleft eye LE so that the viewer may recognize a corresponding 3D image.

FIG. 3 is a plan view illustrating the barrier part 320 of FIG. 1.

Referring to FIGS. 1 and 3, the barrier part 320 includes the firstbarrier substrate 322, the second barrier substrate 324 facing the firstbarrier substrate 322 and the barrier liquid crystal layer (not shown)disposed between the first and second barrier substrates 322 and 324.

The first barrier substrate 322 includes a plurality of elongated andtransparent first electrodes BX1, BX2, BX3, . . . , extending in thehorizontal direction (D1). The second barrier substrate 324 includes aplurality of elongated and transparent second electrodes BY1, BY2, BY3,. . . , extending in the vertical direction (D2). The barriers are eachdefined as a respective area at which the first electrodes BX1, BX2,BX3, . . . and the second electrodes BY1, BY2, BY3, . . . cross witheach other. The barriers are disposed in a matrix pattern.

A vertical pitch Pev of the first electrodes is defined as acenter-to-center distance between the adjacent first electrodes. Ahorizontal pitch Peh of the second electrodes is defined as acenter-to-center distance between the adjacent second electrodes. In thepresent exemplary embodiment, the pitch Pev of the first electrode maybe equal to the pitch Peh of the second electrode.

FIG. 4 is a plan view illustrating the lens part 340 of FIG. 1.

Referring to FIGS. 1 and 4, the lens part 340 includes a plurality oflenses ML. The lenses ML may be disposed to define rows thereofextending in the first direction D1 and columns thereof extending in thesecond direction D2.

For example, each lens ML has a circular shape when viewed from a topplan perspective. For example, a bottom portion of the lens ML has acircular shape in a plan view and an upper portion of the lens ML has aside-view circular shape having a radius less than a radius of thebottom portion. In other words, each lens ML may be a frusto ellipsoidwith a circular base.

In the present exemplary embodiment, centers of four lenses ML form asquare.

A horizontal pitch Plh of the lens ML in the first direction D1 isdefined as a distance between the adjacent lenses ML in the firstdirection D1. A vertical pitch Plv of the lens ML in the seconddirection D2 is defined as a distance between the adjacent lenses ML inthe second direction D2. In the present exemplary embodiment, the pitchPlh of the lens ML in the first direction D1 may be equal to the pitchPlv of the lens ML in the second direction D2.

FIG. 5 is a conceptual diagram illustrating a display area of the imageshown to the viewer at an appropriate user-to-device distance D and asproduced by the combination of the display panel 200 and the directionallight projecting element 300 (320 plus 340) of FIG. 1.

Referring to FIGS. 1 to 5, the appropriate distance D here means thedistance where the 3D image is well displayed to the viewer using thedisplay apparatus. The appropriate distance D is determined from aprincipal point p of a respective lens ML.

When a focal length of the lens ML is f, a distance between theprincipal point p of the lens ML and the barrier part 320 is d and arefractive index of the lens ML is n, the distance d between theprincipal point p of the lens ML and the barrier part 320 may bedetermined in accordance with Equation 1:

$\begin{matrix}{d = \frac{n}{\left( {\frac{1}{f} - \frac{1}{D}} \right)}} & \left\lbrack {{Equation}\mspace{14mu} 1} \right\rbrack\end{matrix}$

A projected viewpoint image portion corresponding to one eye of theviewer at the proper distance D may be referred as PE to properlydisplay the 3D image with one corresponding barrier in the blocking modeand the other in the light-passing mode. The projected area PE of theviewpoint image may be determined based on a distance of two eyes of theviewer. For example, the projected area PE of the viewpoint image mayhave a side view dimension that is substantially the same as thedistance between the two eyes of the viewer. For example, the projectedarea PE of the viewpoint image may be set as a square or circle having acorresponding width or diameter equal to an average distance of two eyesof an average human user.

The plural barriers corresponding to one lens ML may be referred asherein one barrier unit (BU). A pitch Pb of the barrier unit (BU) in aspecific direction may be determined in accordance with followingEquation 2.

$\begin{matrix}{{Pb} = {2 \times {PE} \times \frac{d}{n \times D}}} & \left\lbrack {{Equation}\mspace{14mu} 2} \right\rbrack\end{matrix}$

As shown in FIG. 5, a relationship between Pb and PE may be determinedby similarity of triangles. The pitch Pb of the barrier unit may be asum of a width of a transmitting area of the barrier unit and a width ofa blocking area of the barrier unit. The width of the transmitting areaof the barrier unit may be equal to Pb/2.

When the two eyes of a viewer are disposed in the horizontal direction,the display panel 200 is operated in a corresponding horizontal mode,and a pitch of the barrier unit in the horizontal direction is Pbh. Thepitch Pbh of the barrier unit in the horizontal direction may bedetermined in accordance with Equation 3.

$\begin{matrix}{{Pbh} = {2 \times {PEh} \times \frac{d}{n \times D}}} & \left\lbrack {{Equation}\mspace{14mu} 3} \right\rbrack\end{matrix}$

When two eyes of the viewer are disposed in the vertical direction, thedisplay panel 200 is operated in the vertical mode, and a pitch of thebarrier unit in the vertical direction is Pbv. The pitch Pbv of thebarrier unit in the vertical direction is determined as Equation 4.

$\begin{matrix}{{Pbv} = {2 \times {PEv} \times \frac{d}{n \times D}}} & \left\lbrack {{Equation}\mspace{14mu} 4} \right\rbrack\end{matrix}$

The projected area side dimension PEh of the viewpoint imagecorresponding to one eye of the viewer at the proper distance D in thehorizontal direction may be substantially the same as the projected areadimension PEv of the viewpoint image corresponding to one eye of theviewer at the proper distance D in the vertical direction.Alternatively, the projected area dimension PEh of the viewpoint imagecorresponding to one eye of the viewer at the proper distance D in thehorizontal direction may be different from the projected area dimensionPEv of the viewpoint image corresponding to one eye of the viewer at theproper distance D in the vertical direction according to an arrangementof the lenses ML (for example if the lenses ML is asymmetrical; e.g.,not circular at its base).

A pitch Pl of the lens ML (in other words, the distance between the apexof one lens and the next) in a specific direction may be determined asEquation 5.

$\begin{matrix}{{Pl} = {{Pb} \times \frac{D}{D + \frac{d}{n}}}} & \left\lbrack {{Equation}\mspace{14mu} 5} \right\rbrack\end{matrix}$

As shown in FIG. 5, a relationship between Pl and Pb may be determinedby similarity of triangles.

When two eyes of the viewer are disposed in the horizontal direction,the display panel 200 is operated in the horizontal mode, and a pitch ofthe lens ML in the horizontal direction is Plh. The pitch Plh of thelens ML in the horizontal direction is determined as Equation 6.

$\begin{matrix}{{Plh} = {{Pbh} \times \frac{D}{D + \frac{d}{n}}}} & \left\lbrack {{Equation}\mspace{14mu} 6} \right\rbrack\end{matrix}$

When the two eyes of the viewer are disposed in the vertical direction,the display panel 200 is operated in the vertical mode, and a pitch ofthe lens ML in the vertical direction is Plv. The pitch Ply of the lensML in the vertical direction is determined as Equation 7.

$\begin{matrix}{{Plv} = {{Pbv} \times \frac{D}{D + \frac{d}{n}}}} & \left\lbrack {{Equation}\mspace{14mu} 7} \right\rbrack\end{matrix}$

Referring again to FIG. 3, a width Pbh/2 of the transmitting area of thebarrier in the horizontal direction may be determined as a width of oneof the second electrodes. Alternatively, a width Pbh/2 of thetransmitting area of the barrier in the horizontal direction may bedetermined as a sum of widths of the plural second electrodes. Thus, thepitch Pbh of the barrier unit in the horizontal direction and the pitchPeh of the second electrode have relationship as following Equation 8.Pbh=2×x×Peh  [Equation 8]

Herein, x is a positive integer. When the display apparatus furtherincludes the viewpoint detector 700, x may be a positive integer equalto or greater than 2.

A width Pbv/2 of the transmitting area of the barrier in the verticaldirection may be determined as a width of one of the first electrodes.Alternatively, a width Pbv/2 of the transmitting area of the barrier inthe vertical direction may be determined as a sum of widths of theplural first electrodes. Thus, the pitch Pbv of the barrier unit in thevertical direction and the pitch Pev of the first electrode haverelationship as following Equation 9.Pbv=2×y×Pev  [Equation 9]

Herein, y is a positive integer. When the display apparatus furtherincludes the viewpoint detector 700, y may be a positive integer equalto or greater than 2. In the present exemplary embodiment, y may beequal to x.

FIG. 6 is a conceptual diagram illustrating a plurality of the barrierscorresponding to one lens ML of FIG. 1 where the one lens ML has acircular base.

Referring to FIG. 6, one lens ML corresponds to plural barriers. Forexample, one lens ML corresponds to the barriers disposed in an M by Mmatrix. In the present exemplary embodiment, one lens ML1 corresponds tofour, selectively activateable barriers B11, B12, B21 and B22 disposedin a two by two matrix (2×2 matrix). For example, the circular lens ML1corresponds to four square barriers B11, B12, B21 and B22. Centers ofthe first to fourth barriers B11, B12, B21 and B22 may form a square. Inthe present exemplary embodiment, x is 1 and y is 1 in Equations 8 and9.

From the viewpoint of the viewer, the area of one lens ML1 of the lenspart 340 substantially overlaps four barriers B11, B12, B21 and B22 ofthe barrier part 320 as shown in FIG. 6. When the lens part 340 and thebarrier part are seen as disposed on a same plane, and due to aprojection magnifying factor; a radius of the lens ML1 may not be equalto a length of a side of one of the barriers B11, B12, B21 and B22. Forexample, the radius of the lens ML1 may be slightly less than the lengthof the side of one of the barriers B11, B12, B21 and B22.

Each of the barriers B11, B12, B21 and B22 is selectively placed in arespective one of the light transmitting state and the light blockingstate. The light transmitted through the barriers having thetransmitting states is refracted at the lens ML1 and transmitted(projected) to a respective one eye of the viewer while the blacked outimagery of the barriers having the light blocking states can be said tobe projected to the other eye.

FIGS. 7A and 7B are conceptual diagrams corresponding to states of thebarriers B11, B12, B21 and B22 corresponding to one lens ML1 of FIG. 1in the horizontal mode.

Referring to FIG. 7A, a first barrier B11 and a third barrier B21 whichare adjacent to each other in the vertical direction have thetransmitting states during the first subframe in the horizontal mode. Asecond barrier B12 and a fourth barrier B22 which are adjacent to eachother in the vertical direction have the blocking states during thefirst subframe in the horizontal mode.

The light transmitting the barriers B11 and B21 having the transmittingstates is refracted at the lens ML1 and transmitted to (projected to)the right eye RE of the viewer.

Referring to FIG. 7B, the second barrier B12 and the fourth barrier B22which are adjacent to each other in the vertical direction have thetransmitting states during the second subframe in the horizontal mode.The first barrier B11 and the third barrier B21 which are adjacent toeach other in the vertical direction have the blocking states during thesecond subframe in the horizontal mode.

The light transmitting the barriers B12 and B22 having the transmittingstates is refracted at the lens ML1 and transmitted to (projected to)the left eye LE of the viewer during that subframe.

Therefore, the viewer may recognize the 3D image in the horizontal modedue to the alternating projections to the left and right eyes during therespective subframes.

FIGS. 8A and 8B are conceptual diagrams corresponding to states of thebarriers B11, B12, B21 and B22 corresponding to one lens ML1 of FIG. 1in the vertical mode.

Referring to FIG. 8A, the third barrier B21 and the fourth barrier B22which are adjacent to each other in the horizontal direction have thetransmitting states during the first subframe in the vertical mode. Thefirst barrier B11 and the second barrier B12 which are adjacent to eachother in the horizontal direction have the blocking states during thefirst subframe in the vertical mode.

The light transmitting the barriers B21 and B22 having the transmittingstates is refracted at the lens ML1 and transmitted to the right eye REof the viewer during the respective subframe.

Referring to FIG. 8B, the first barrier B11 and the second barrier B12which are adjacent to each other in the horizontal direction have thetransmitting states during the second subframe in the vertical mode. Thethird barrier B21 and the fourth barrier B22 which are adjacent to eachother in the horizontal direction have the blocking states during thefirst subframe in the vertical mode.

The light transmitting the barriers B11 and B12 having the transmittingstates is refracted at the lens ML1 and transmitted to the left eye LEof the viewer.

Therefore, the viewer may recognize the 3D image in the vertical modeduring the respective subframes.

According to the present exemplary embodiment, the display apparatus maydisplay the 3D image when two eyes of the viewer are either disposed inthe horizontal direction or in the vertical direction by using thebarriers disposed in the matrix form and the lenses corresponding to thebarriers.

FIG. 9 is a conceptual diagram illustrating another embodiment wherein agreater plurality of barriers correspond to one lens of a displayapparatus as compared to the exemplary embodiment of FIG. 6.

For the case of FIG. 9, the display apparatus and the method ofdisplaying the 3D image according to the present exemplary embodimentare substantially the same as the display apparatus and the method ofdisplaying the 3D image explained referring to FIGS. 1 to 8B except fora structure of the barrier part 320, a structure of the lens part 340and an operation of the lens part. Thus, the same reference numeralswill be used to refer to the same or like parts as those described inFIGS. 1 to 8B and any repetitive explanation concerning the aboveelements will be omitted.

Referring to FIGS. 1 and 9, the display apparatus includes a lightsource part 100, a display panel 200, a directional light projectingelement 300, a light source driver 400, a display panel driver 500 and abarrier driver 600. The display apparatus may further include aviewpoint detector 700.

One lens ML corresponds to the plural barriers. For example, one lens MLcorresponds to the barriers disposed in an M by M matrix where M isgreater than 2. In the present exemplary embodiment, one lens ML1corresponds to 36 barriers B11 to B66 disposed in a six by six matrix.For example, the circular lens ML1 corresponds to 36 square barriers B11to B66. In the present exemplary embodiment, x is 3 and y is 3 inEquations 8 and 9.

In the present exemplary embodiment, the width of the transmitting areaof the barrier corresponds to widths of three barriers so that thedisplay apparatus may be operated in the inclination mode, in which twoeyes of the viewer are disposed in an inclined direction (e.g., 45degrees) with respect to the display panel 200. The operation of thedisplay panel 200 in the inclination mode may be explained referring toFIGS. 12A and 12B in detail. In addition, the transmitting states andthe blocking states may be precisely adjusted according to the move ofthe viewpoint of the viewer so that a viewpoint tracking method may bewell applied to the display apparatus. The viewpoint tracking method maybe further explained referring to FIGS. 13A to 13C in detail.

Each of the barriers B11 to B66 has one of the transmitting state andthe blocking state. The light transmitting the barriers having thetransmitting states is refracted at the lens ML1 and transmitted to theeye of the viewer.

FIGS. 10A and 10B are conceptual diagrams corresponding to states of thebarriers B11 to B66 corresponding to one lens ML1 of FIG. 9 in thehorizontal mode.

Referring to FIG. 10A, barriers in first to third columns B11 to B13,B21 to B23, B31 to B33, B41 to B43, B51 to B53 and B61 to B63 have thetransmitting states during the first subframe in the horizontal mode.Barriers in fourth to sixth columns B14 to B16, B24 to B26, B34 to B36,B44 to B46, B54 to B56 and B64 to B66 have the blocking states duringthe first subframe in the horizontal mode.

The light transmitting the barriers B11 to B13, B21 to B23, B31 to B33,B41 to B43, B51 to B53 and B61 to B63 having the transmitting states isrefracted at the lens ML1 and transmitted to the right eye RE of theviewer.

Referring to FIG. 10B, the barriers in the fourth to sixth columns B14to B16, B24 to B26, B34 to B36, B44 to B46, B54 to B56 and B64 to B66have the transmitting states during the second subframe in thehorizontal mode. The barriers in the first to third columns B11 to B13,B21 to B23, B31 to B33, B41 to B43, B51 to B53 and B61 to B63 have theblocking states during the second subframe in the horizontal mode.

The light transmitting the barriers B14 to B16, B24 to B26, B34 to B36,B44 to B46, B54 to B56 and B64 to B66 having the transmitting states isrefracted at the lens ML1 and transmitted to the left eye LE of theviewer.

Therefore, the viewer may recognize the 3D image in the horizontal mode.

FIGS. 11A and 11B are conceptual diagrams corresponding to states of thebarriers B11 to B66 corresponding to one lens ML1 of FIG. 9 in thevertical mode.

Referring to FIG. 11A, barriers in fourth to sixth rows B41 to B46, B51to B56 and B61 to B66 have the transmitting states during the firstsubframe in the vertical mode. Barriers in first to third rows B11 toB16, B21 to B26 and B31 to B36 have the blocking states during the firstsubframe in the vertical mode.

The light transmitting the barriers B41 to B46, B51 to B56 and B61 toB66 having the transmitting states is refracted at the lens ML1 andtransmitted to the right eye RE of the viewer.

Referring to FIG. 11B, the barriers in the first to third rows B11 toB16, B21 to B26 and B31 to B36 have the transmitting states during thesecond subframe in the vertical mode. The barriers in the fourth tosixth rows B41 to B46, B51 to B56 and B61 to B66 have the blockingstates during the first subframe in the vertical mode.

The light transmitting the barriers B11 to B16, B21 to B26 and B31 toB36 having the transmitting states is refracted at the lens ML1 andtransmitted to the left eye LE of the viewer.

Therefore, the viewer may recognize the 3D image in the vertical mode.

FIGS. 12A and 12B are conceptual diagrams corresponding to states of thebarriers corresponding to one lens ML of FIG. 9 in an inclination mode(e.g., 45 degrees).

Referring to FIG. 12A, barriers B61, B52, B43, B34, B25, B16, B62, B53,B44, B35, B26, B63, B54, B45, B36, B64, B5, B46, B65, B56 and B66, whichare adjacent in an inclined direction, have the transmitting statesduring the first subframe in the inclination mode. Barriers B51, B42,B33, B24, B15, B41, B32, B23, B14, B31, B22, B13, B21, B12, and B11,which are adjacent in the inclined direction, have the blocking statesduring the first subframe in the inclination mode.

Only the barriers corresponding to one lens ML1 are illustrated in FIG.12A. Other barriers may be arranged such that the barriers having thetransmitting states are continuously connected to the barriers in FIG.12A in the inclined direction and the barriers having the blockingstates are continuously connected to the barriers in FIG. 12A in theinclined direction.

The light transmitting the barriers B61, B52, B43, B34, B25, B16, B62,B53, B44, B35, B26, B63, B54, B45, B36, B64, B5, B46, B65, B56 and B66having the transmitting states is refracted at the lens ML1 andtransmitted to the right eye RE of the viewer.

Referring to FIG. 12B, the barriers B51, B42, B33, B24, B15, B41, B32,B23, B14, B31, B22, B13, B21, B12, and B11, which are adjacent in theinclined direction, have the transmitting states during the secondsubframe in the inclination mode. The barriers B61, B52, B43, B34, B25,B16, B62, B53, B44, B35, B26, B63, B54, B45, B36, B64, B5, B46, B65, B56and B66, which are adjacent in the inclined direction, have the blockingstates during the second subframe in the inclination mode.

The light transmitting the barriers B51, B42, B33, B24, B15, B41, B32,B23, B14, B31, B22, B13, B21, B12, and B11 having the transmittingstates is refracted at the lens ML1 and transmitted to the left eye LEof the viewer.

Therefore, the viewer may recognize the 3D image in the inclinationmode.

In the inclination mode, the barriers having the transmitting states aredisposed in a direction substantially perpendicular to a line connectingtwo eyes of the viewer. Although the two eyes of the viewer are inclinedin an angle of say, 45 degree with respect to the display panel 200 inFIGS. 12A and 12B, the inclined angle of the two eyes of the viewer ofthe present invention is not limited thereto and the particular barriersthat are selectively switched into the light-passing mode versus thelight-blocking mode may be varied so as to correspond to other angles ofinclination.

FIGS. 13A to 13C are conceptual diagrams corresponding to states of thebarriers corresponding to one lens ML of FIG. 9 when a viewpoint of theviewer moves in the horizontal direction relative to the respective onelens ML.

For example, in FIGS. 13A to 13C, the display panel 200 is operated inthe horizontal mode and the viewpoint moves in the same subframe (forexample, the first subframe).

Referring to FIG. 13A, the barriers in the first to third columns B11 toB13, B21 to B23, B31 to B33, B41 to B43, B51 to B53 and B61 to B63 havethe transmitting states. The barriers in the fourth to sixth columns B14to B16, B24 to B26, B34 to B36, B44 to B46, B54 to B56 and B64 to B66have the blocking states.

The light transmitting the barriers B11 to B13, B21 to B23, B31 to B33,B41 to B43, B51 to B53 and B61 to B63 having the transmitting states isrefracted at the lens ML1 and transmitted to the right eye RE of theviewer.

Referring to FIG. 13B, the viewpoint of the viewer moves in thehorizontal direction compared to the viewpoint in FIG. 13A. Theviewpoint detector 700 detects the move of the viewpoint of the viewer.The barrier driver 600 may adjust the transmitting states of thebarriers and the blocking states of the barriers according to the moveof the viewpoint of the viewer.

A moving direction of the barriers having the transmitting states may beopposite to a moving direction of the viewpoint of the viewer.

The barriers in first, second and sixth columns B11, B12, B16, B21, B22,B26, B31, B32, B36, B41, B42, B46, B51, B52, B56, B61, B62 and B66 havethe transmitting states. The barriers in third to fifth columns B13 toB15, B23 to B25, B33 to B35, B43 to B45, B53 to B55 and B63 to B65 havethe blocking states.

The light transmitting the barriers B11, B12, B16, B21, B22, B26, B31,B32, B36, B41, B42, B46, B51, B52, B56, B61, B62 and B66 having thetransmitting states is refracted at the lens ML1 and transmitted to theright eye RE of the viewer.

Referring to FIG. 13C, the viewpoint of the viewer moves in thehorizontal direction compared to the viewpoint in FIG. 13B. Theviewpoint detector 700 detects the move of the viewpoint of the viewer.The barrier driver 600 may adjust the transmitting states of thebarriers and the blocking states of the barriers according to the moveof the viewpoint of the viewer.

The barriers in first, fifth and sixth columns B11, B15, B16, B21, B25,B26, B31, B35, B36, B41, B45, B46, B51, B55, B56, B61, B65 and B66 havethe transmitting states. The barriers in second to fourth columns B12 toB14, B22 to B24, B32 to B34, B42 to B44, B52 to B54 and B62 to B64 havethe blocking states.

The light transmitting the barriers B11, B15, B16, B21, B25, B26, B31,B35, B36, B41, B45, B46, B51, B55, B56, B61, B65 and B66 having thetransmitting states is refracted at the lens ML1 and transmitted to theright eye RE of the viewer.

Therefore, the viewer may recognize the 3D image using the viewpointtracking method when the viewpoint of the viewer moves.

Although the viewpoint of the viewer moves in the horizontal mode inFIGS. 13A to 13C, the present disclosure of invention is not limitedthereto. According to the present viewpoint tracking method, the viewermay recognize the 3D image using the viewpoint tracking method in thevertical mode and/or in the inclination mode.

According to the present exemplary embodiment, the display apparatus maydisplay the 3D image when two eyes of the viewer are disposed in thehorizontal direction, in the vertical direction and/or in theinclination direction using the barriers disposed in the matrix form andthe lenses corresponding to the barriers. In addition, the displayapparatus may display the 3D image when the viewpoint of the viewermoves relative to the respective lenses.

FIG. 14 is a plan view illustrating a lens part 340A according to anexemplary embodiment.

The display apparatus and the method of displaying the 3D imageaccording to the present exemplary embodiment are substantially the sameas the display apparatus and the method of displaying the 3D imageexplained referring to FIGS. 1 to 8B except for the shapes, sizes and/orthe arrangements of the individual lenses ML of the lens part. Thus, thesame reference numerals will be used to refer to the same or like partsas those described in FIGS. 1 to 8B and any repetitive explanationconcerning the above elements will be omitted.

Referring to FIGS. 1 and 14, the display apparatus includes a lightsource part 100, a display panel 200, a directional light projectingelement 300, a light source driver 400, a display panel driver 500 and abarrier driver 600. The display apparatus may further include aviewpoint detector 700.

The directional light projecting element 300 includes a barrier part 320and a lens part 340A.

The lens part 340A includes a plurality of lenses ML. The lenses ML maybe disposed in the first direction D1 and the second direction D2 toform respective rows and columns.

For example, each of the lens ML has a circular shape at its base. Forexample, a bottom portion of the lens ML has a circular shape in a planview and an upper portion of the lens ML has a circular shape having aradius less than a radius of the bottom portion.

In the present exemplary embodiment, centers of four lenses ML form asquare.

A pitch Plh of the lens ML in the first direction D1 is defined as adistance between the adjacent lenses ML in the first direction D1. Apitch Plv of the lens ML in the second direction D2 is defined as adistance between the adjacent lenses ML in the second direction D2. Inthe present exemplary embodiment, the pitch Plh of the lens ML in thefirst direction D1 may be equal to the pitch Plv of the lens ML in thesecond direction D2.

The lens part 340A further includes a light blocking material BM (blackmatrix) disposed where the lenses ML are not disposed. The lightblocking material BM blocks the light, which transmitted from thebarrier part 320, at an area not corresponding to the lenses ML. Acrosstalk may be prevented by the light blocking material BM.

According to the present exemplary embodiment, the display apparatus maydisplay the 3D image when two eyes of the viewer are disposed in thehorizontal direction and in the vertical direction using the barriersdisposed in the matrix form and the lenses corresponding to thebarriers.

FIG. 15 is a plan view illustrating a lens part 340B according to anexemplary embodiment.

The display apparatus and the method of displaying the 3D imageaccording to the present exemplary embodiment are substantially the sameas the display apparatus and the method of displaying the 3D imageexplained referring to FIGS. 1 to 8B except for the shapes, sizes andarrangement of the lenses ML of the lens part. Thus, the same referencenumerals will be used to refer to the same or like parts as thosedescribed in FIGS. 1 to 8B and any repetitive explanation concerning theabove elements will be omitted.

Referring to FIGS. 1 and 15, the display apparatus includes a lightsource part 100, a display panel 200, a directional light projectingelement 300, a light source driver 400, a display panel driver 500 and abarrier driver 600. The display apparatus may further include aviewpoint detector 700.

The directional light projecting element 300 includes a barrier part 320and a lens part 340B.

The lens part 340B includes a plurality of lenses ML. The lenses ML maybe packed in accordance with a hexagonal packing arrangement such thatthey are disposed in the first direction D1 and a direction inclined inan inclined direction from the first direction D1. For example, theinclined direction may have 60 degree.

For example, the lens ML has a circular shape. For example, a bottomportion of the lens ML has a circular shape in a plan view and an upperportion of the lens ML has a circular shape having a radius less than aradius of the bottom portion.

In the present exemplary embodiment, centers of three lenses ML form anisometric triangle. An area where the lenses ML are not disposedrelatively decreases so that a light efficiency of the display apparatusmay be improved.

A pitch Plh of the lens ML in the first direction D1 is defined as adistance between the adjacent lenses ML in the first direction D1. Apitch Plv of the lens ML in the second direction D2 is defined as adistance between the adjacent lenses ML in the second direction D2. Inthe present exemplary embodiment, the pitch Plh of the lens ML in thefirst direction D1 may be greater than the pitch Plv of the lens ML inthe second direction D2. Accordingly, the pitch Pbh of the barrier unitin the first direction D1 may be greater than the pitch Pbv of thebarrier unit in the second direction D2

According to the present exemplary embodiment, the display apparatus maydisplay the 3D image when two eyes of the viewer are disposed in thehorizontal direction and in the vertical direction using the barriersdisposed in the matrix form and the lenses corresponding to thebarriers.

FIG. 16 is a plan view illustrating a lens part 340C according to anexemplary embodiment.

The display apparatus and the method of displaying the 3D imageaccording to the present exemplary embodiment are substantially the sameas the display apparatus and the method of displaying the 3D imageexplained referring to FIGS. 1 to 8B except for the shapes, sizes,arrangement of the lenses of the lens part and the presence of the blackmatrix (BM). Thus, the same reference numerals will be used to refer tothe same or like parts as those described in FIGS. 1 to 8B and anyrepetitive explanation concerning the above elements will be omitted.

Referring to FIGS. 1 and 16, the display apparatus includes a lightsource part 100, a display panel 200, a directional light projectingelement 300, a light source driver 400, a display panel driver 500 and abarrier driver 600. The display apparatus may further include aviewpoint detector 700.

The directional light projecting element 300 includes a barrier part 320and a lens part 340C.

The lens part 340C includes a plurality of lenses ML. The lenses ML maybe disposed in the first direction D1 and a direction inclined in aninclined direction from the first direction D1. For example, theinclined direction may have 60 degree.

For example, the lens ML has a circular shape. For example, a bottomportion of the lens ML has a circular shape in a plan view and an upperportion of the lens ML has a circular shape having a radius less than aradius of the bottom portion.

In the present exemplary embodiment, centers of three lenses ML form anisometric triangle. An area where the lenses ML are not disposedrelatively decreases so that a light efficiency of the display apparatusmay be improved.

A pitch Plh of the lens ML in the first direction D1 is defined as adistance between the adjacent lenses ML in the first direction D1. Apitch Plv of the lens ML in the second direction D2 is defined as adistance between the adjacent lenses ML in the second direction D2. Inthe present exemplary embodiment, the pitch Plh of the lens ML in thefirst direction D1 may be greater than the pitch Plv of the lens ML inthe second direction D2. Accordingly, the pitch Pbh of the barrier unitin the first direction D1 may be greater than the pitch Pbv of thebarrier unit in the second direction D2

The lens part 340C further includes a light blocking material BMdisposed where the lenses ML are not disposed. The light blockingmaterial BM blocks the light, which transmitted from the barrier part320, at an area not corresponding to the lenses ML. A crosstalk may bereduced by the light blocking material BM.

According to the present exemplary embodiment, the display apparatus maydisplay the 3D image when two eyes of the viewer are disposed in thehorizontal direction and in the vertical direction using the barriersdisposed in the matrix form and the lenses corresponding to thebarriers.

FIG. 17A is a plan view illustrating a lens part 340D according to anexemplary embodiment. FIG. 17B is a cross-sectional view cut along aline I-I′ in FIG. 17A.

The display apparatus and the method of displaying the 3D imageaccording to the present exemplary embodiment are substantially the sameas the display apparatus and the method of displaying the 3D imageexplained referring to FIGS. 1 to 8B except for respective shapes andsizes of the lenses of the lens part. Thus, the same reference numeralswill be used to refer to the same or like parts as those described inFIGS. 1 to 8B and any repetitive explanation concerning the aboveelements will be omitted.

Referring to FIGS. 1, 17A and 17B, the display apparatus includes alight source part 100, a display panel 200, a directional lightprojecting element 300, a light source driver 400, a display paneldriver 500 and a barrier driver 600. The display apparatus may furtherinclude a viewpoint detector 700.

The directional light projecting element 300 includes a barrier part 320and a lens part 340D.

The lens part 340D includes a plurality of lenses ML. The lenses ML maybe disposed in the first direction D1 and the second direction D2 tothereby define rows and columns.

For example, a bottom portion of the lens ML has a square shape and anupper portion of the lens ML has a circular shape. The lens part 340Ddoes not have a portion where the lenses are not disposed so that alight efficiency of the display apparatus may be improved.

In the present exemplary embodiment, centers of four lenses ML form asquare.

A pitch Plh of the lens ML in the first direction D1 is defined as adistance between the adjacent lenses ML in the first direction D1. Apitch Plv of the lens ML in the second direction D2 is defined as adistance between the adjacent lenses ML in the second direction D2. Inthe present exemplary embodiment, the pitch Plh of the lens ML in thefirst direction D1 may be equal to the pitch Plv of the lens ML in thesecond direction D2.

According to the present exemplary embodiment, the display apparatus maydisplay the 3D image when two eyes of the viewer are disposed in thehorizontal direction and in the vertical direction using the barriersdisposed in the matrix form and the lenses corresponding to thebarriers.

FIG. 18A is a plan view illustrating a lens part 340E according to anexemplary embodiment (hexagonal packing embodiment). FIG. 18B is across-sectional view cut along a line II-II′ in FIG. 18A.

The display apparatus and the method of displaying the 3D imageaccording to the present exemplary embodiment are substantially the sameas the display apparatus and the method of displaying the 3D imageexplained referring to FIGS. 1 to 8B except for the shapes, sizes andarrangement of the lenses of the lens part. Thus, the same referencenumerals will be used to refer to the same or like parts as thosedescribed in FIGS. 1 to 8B and any repetitive explanation concerning theabove elements will be omitted.

Referring to FIGS. 1, 18A and 18B the display apparatus includes a lightsource part 100, a display panel 200, a directional light projectingelement 300, a light source driver 400, a display panel driver 500 and abarrier driver 600. The display apparatus may further include aviewpoint detector 700.

The directional light projecting element 300 includes a barrier part 320and a lens part 340E.

The lens part 340E includes a plurality of lenses ML. The lenses ML maybe disposed in the first direction D1 and a direction inclined in aninclined direction from the first direction D1. For example, theinclined direction may have 60 degree.

For example, a bottom portion of the lens ML has a regular hexagonalshape and an upper portion of the lens ML has a circular shape. The lenspart 340E does not have a portion where the lenses are not disposed sothat a light efficiency of the display apparatus may be improved.

In the present exemplary embodiment, centers of three lenses ML form anisometric triangle.

A pitch Plh of the lens ML in the first direction D1 is defined as adistance between the adjacent lenses ML in the first direction D1. Apitch Plv of the lens ML in the second direction D2 is defined as adistance between the adjacent lenses ML in the second direction D2. Inthe present exemplary embodiment, the pitch Plh of the lens ML in thefirst direction D1 may be less than the pitch Plv of the lens ML in thesecond direction D2. Accordingly, the pitch Pbh of the barrier unit inthe first direction D1 may be less than the pitch Pbv of the barrierunit in the second direction D2

According to the present exemplary embodiment, the display apparatus maydisplay the 3D image when two eyes of the viewer are disposed in thehorizontal direction and in the vertical direction using the barriersdisposed in the matrix form and the lenses corresponding to thebarriers.

According to the exemplary embodiments of the present disclosure ofinvention as explained above, the display apparatus may properlyrepresent the 3D image according to a direction of two eyes of theviewer and/or according to a lateral shift of the eyes relative tospecific ones of the lenses (ML).

The foregoing is illustrative of the present disclosure of invention andis not to be construed as limiting thereof. Although a few exemplaryembodiments in accordance with the present disclosure have beenprovided, those skilled in the art will readily appreciate in light ofthe foregoing that many modifications are possible in the exemplaryembodiments without materially departing from the novel teachings andadvantages of the present disclosure. Accordingly, all suchmodifications are intended to be included within the scope of thepresent teachings. In the claims, means-plus-function clauses areintended to cover the structures described herein as performing therecited function and not only structural equivalents but alsofunctionally equivalent structures. Therefore, it is to be understoodthat the foregoing is illustrative of the present disclosure ofinvention and is not to be construed as limited it to the specificexemplary embodiments disclosed, and that modifications to the disclosedexemplary embodiments, as well as other exemplary embodiments, areintended to be included within the scope of the present teachings.

What is claimed is:
 1. A display apparatus comprising: a display panelconfigured to display a first image during a first subframe and a secondimage during a second subframe; a light source part configured toprovide backlighting light to the display panel; and a directional lightprojecting element disposed between the display panel and the lightsource part, and including a barrier part and a lens part, the lens partbeing disposed above the barrier part; wherein the barrier part has aplurality of selectively activateable barriers defined by acorresponding plurality of elongated first electrodes extending in afirst direction and a plurality of elongated second electrodes extendingin a second direction different from the first direction and thuscrossing with the elongated first electrodes; and wherein the lens parthas a plurality of lenses disposed in accordance with an areatessellating pattern, each of the lenses having a coverage areacorresponding to a respective subplurality of the barriers, and whereina vertical pitch of the first electrode is equal to a horizontal pitchof the second electrode, and the vertical pitch of the elongated firstelectrodes is defined as a center-to-center distance between theadjacent elongated first electrodes, and the horizontal pitch of theelongated second electrodes is defined as a center-to-center distancebetween the adjacent elongated second electrodes, and wherein thebarriers have a matrix configuration defined by crossing of theelongated first electrodes and the elongated second electrodes.
 2. Thedisplay apparatus of claim 1, wherein each one lens corresponds to arespective subplurality of barriers disposed in an M by M matrix, whereM is a positive integer equal to or greater than
 2. 3. The displayapparatus of claim 1, wherein each lens has a circular shape at least ata base portion thereof.
 4. The display apparatus of claim 3, whereincenters of four lenses adjacent to each other form a square.
 5. Thedisplay apparatus of claim 3, wherein centers of three lenses adjacentto each other form an isometric triangle.
 6. The display apparatus ofclaim 3, wherein the lens part further comprises a light blockingmaterial disposed where the lenses are not disposed.
 7. The displayapparatus of claim 1, wherein: a bottom portion of the lens has a squareshape, and an upper portion of the lens has a circular shape.
 8. Thedisplay apparatus of claim 1, wherein a bottom portion of the lens has aregular hexagonal shape, and an upper portion of the lens has a circularshape.
 9. The display apparatus of claim 1, wherein a predefined properdistance for a viewer to view a three-dimensional (“3D”) image from aprincipal point of the lens is equal to D, a focal length of the lens isequal to f, a distance between the principal point of the lens and thebarrier part is equal to d, a refractive index of the lens is equal ton, and a relationship between the said parameters is substantiallydefined by the following equation:$d = {\frac{n}{\left( {\frac{1}{f} - \frac{1}{D}} \right)}.}$
 10. Thedisplay apparatus of claim 9, wherein a projection area dimension of aviewpoint image corresponding to one eye of the viewer at the properdistance D is equal to PE, a pitch of a barrier unit, which includes thebarriers corresponding to one lens, in the first direction is equal toPb, and ${Pb} = {2 \times {PE} \times {\frac{d}{n \times D}.}}$
 11. Thedisplay apparatus of claim 10, wherein a pitch of the lens in the firstdirection is Pl, and ${Pl} = {{Pb} \times {\frac{D}{D + \frac{d}{n}}.}}$12. The display apparatus of claim 10, wherein the projected areadimension PE of the viewpoint image corresponding to one eye of theviewer at the proper distance D is equal to a distance between two eyesof an average viewer.
 13. The display apparatus of claim 1, wherein: thedisplay panel is operable in a horizontal mode, in which two eyes of aviewer are disposed in a horizontal direction relative to acorresponding horizontal axis of the display panel, the display panel isoperable in a vertical mode, in which two eyes of the viewer aredisposed in a vertical direction relative to the horizontal axis of thedisplay panel, those of the barriers that are selectively activated tohave respective light transmitting states in each subframe are disposedas lines extending in the vertical direction when in the horizontalmode, and those of the barriers that are selectively activated to haverespective light transmitting states in each subframe are disposed aslines extending in the horizontal direction when in the vertical mode.14. The display apparatus of claim 1, wherein the display panel isoperable in an inclination mode, in which two eyes of a viewer aredisposed in a direction inclined with respect to the horizontal axis ofthe display panel, and those of the barriers that are selectivelyactivated to have respective light transmitting states in each subframeare disposed as lines extending in a direction substantiallyperpendicular to a line connecting two eyes of the viewer in theinclination mode.
 15. The display apparatus of claim 1, furthercomprising a viewpoint detector/determiner configured to track and/ordetermine a viewpoint of a viewer.
 16. The display apparatus of claim15, wherein the transmitting states of the barriers of the barrier partand the blocking states of the barriers of the barrier part are adjustedaccording to a move of the viewpoint of the viewer relative to lenses ofthe lens part.
 17. A method of displaying a three-dimensional (“3D”)image, the method comprising: providing first image data to a displaypanel during a first subframe and different second image data to thedisplay panel during a second subframe; providing backlighting light tothe display panel; selectively projecting the light through adirectional light projecting element in accordance with a first set ofprojecting angles during the first subframe and in accordance with adifferent second set of projecting angles during the second subframe,and wherein the directional light projecting element comprises a barrierpart and a lens part and wherein the barrier part has a plurality ofbarriers defined as a plurality of elongated first electrodes extendingin a first direction and a plurality of elongated second electrodesextending in a second direction different from the first direction andcrossing with the elongated first electrodes; wherein the lens part hasa plurality of lenses disposed in a first direction and a seconddirection crossing the first direction, each of the lenses correspondingto a subplurality of the barriers, and where the method includes:refracting light selectively passed through the barrier part usingrespective lenses of the lens part, and wherein a vertical pitch of thefirst electrode is equal to a horizontal pitch of the second electrode,and the vertical pitch of the elongated first electrodes is defined as acenter-to-center distance between the adjacent elongated firstelectrodes, and the horizontal pitch of the elongated second electrodesis defined as a center-to-center distance between the adjacent elongatedsecond electrodes, and wherein the barriers have a matrix configurationdefined by crossing of the elongated first electrodes and the elongatedsecond electrodes.
 18. The method of claim 17, wherein one lenscorresponds to the barriers disposed in an M by M matrix, and M is apositive integer equal to or greater than
 2. 19. The method of claim 17,wherein a predetermined proper distance for a viewer to view the 3Dimage from a principal point of the lens is equal to D, a focal lengthof the lens is equal to f, a distance between the principal point of thelens and the barrier part is equal to d, a refractive index of the lensis equal to n, and$d = {\frac{n}{\left( {\frac{1}{f} - \frac{1}{D}} \right)}.}$
 20. Themethod of claim 19, wherein a projected area of a viewpoint imagecorresponding to one eye of the viewer at the proper distance D has adimension of PE, a pitch of a barrier unit, which includes the barrierscorresponding to one lens, in the first direction is equal to Pb, and${Pb} = {2 \times {PE} \times {\frac{d}{n \times D}.}}$
 21. The methodof claim 20, wherein a pitch of the lens in the first direction is equalto Pl, and ${Pl} = {{Pb} \times {\frac{D}{D + \frac{d}{n}}.}}$